Figure 2.

Fluoroscopic position of the cryoballoon with no contrast injection (A) during ablation at the superior pulmonary vein in a patient in the no-contrast (NC) group requiring interruption of the freezing cycle after 50 s due to inadequate temperature decrease (C, dashed line). The intracardiac recordings (D) from the Achieve^TM inner lumen spiral mapping catheter show no effect on the pulmonary vein potential (Achieve12 to Achieve45). Recordings from four surface electrocardiographic leads are also shown. After fluoroscopic adjustment of the cryoballoon position without contrast injection (B) an adequate temperature decrease (C) resulting in progressive delay and subsequent electrical isolation of the pulmonary vein (E).